DNA that is synthesized by isolated Ehrlich ascites nuclei, then secreted into the supernatant, will be characterized by attempting to hybridize with known species of RNA (r-RNA, m-RNA etc.). Attempts will be made, using hybridization, to determine whether this DNA is similar to that found in the cytoplasmic fractions of these cells. The kinetics of labeling of the DNA found as such, and as DNA-RNA hybrid, will be studied to learn whether the sequence indicates synthesis by templating from RNA, and whether the DNA made is in turn used for templating RNA. The RNA made by these nuclei will be characterized. The distribution of proteins and RNA along DNA will be studied and correlated with DNA templating activity. A flow microfluorimeter will be set up, especially for use in the search for, and study of, biological systems that amplify DNA.